Thread's not quite what you think. I have a GPS mount already--a windshield suction mount with a long arm on it. I like the mount, but the thing bounces around like crazy and rattles off of the dash.
What I'd like to do is secure the bottom of the arm to the dash somehow so that it can't bounce around whenever my speedometer hits 50. I've had great luck with 3M Dual Lock in the past, but there's no way in hell I'm using that stuff on my dashboard. Would something less permanent (i.e., Velcro, which has a much less-strong glue than Dual Lock) work well enough, or even those 3M Command adhesive strips that come off cleanly?